This is the editor's letter in the current issue of The Week magazine.

The most telling aspect of a crazed partisan's 50-round assault on Republican lawmakers last week was that it was not all that surprising. Horrifying, yes. Shocking, no. Mass shootings have become as commonplace in this country as wildfires; partisan hatred has reached a fever pitch unseen since the 1960s, and perhaps the 1850s. Millions of people despise the other political tribe with a visceral passion, and the other tribe loathes them right back. Two decades ago, according to Pew Research, just 21 percent of Republicans and 17 percent of Democrats gave the other party a "very unfavorable" rating. By last year, that contempt rating had shot up to 58 percent and 55 percent, respectively. More troubling still: 45 percent of Republicans and 41 percent of Democrats view the other party as "a threat to the nation's well-being." Combine apocalyptic panic with the most polarizing presidency in modern times, frequent and increasingly violent conflicts between far-left and far-right protesters, and 300 million or so firearms, and you've got a nation whose RPM needle is climbing into the red zone.

I worry about where we are headed. Democrats and Republicans are self-segregating into geographic, cultural, and media ghettos of like-minded souls, making it easier to demonize those who are outside the wall. Compromise is dead; giving an inch to Them, a form of treason. The ongoing investigation by special counsel Robert Mueller might find no wrongdoing, but if he charges that Trump aides engaged in collusion, quid pro quos, and/or financial transactions with Russia, or concludes that the president obstructed justice, we will be thrust into a constitutional crisis. Trump will likely denounce any attempt to force him from office as "a coup." Tens of millions of furious partisans will believe him. What happens then? Our norms, institutions, and the rule of law will be sorely tested, and we'll find out what remains of the ties that bind us.